The Lanhao Environmental Protection PQ-2000 blast furnace pulverized coal injection lance is specifically designed for coal injection in blast furnaces, featuring a simple structure and convenient operation. The lance mainly consists of the lance tube, nozzle sleeve, multi-hole nozzle, and nozzle cap. Its unique feature is that the head of the pulverized coal lance tube is equipped with a multi-hole nozzle, which evenly distributes multiple round holes, cleverly dividing the coal powder airflow into multiple fine streams. These streams rapidly mix with the blast furnace hot air, ensuring full combustion of the pulverized coal, thereby not only improving the utilization rate of coal powder but also enhancing the operational efficiency of the blast furnace.

       During operation, the lance is inserted into the furnace body through a bayonet end to begin its task. When the blast furnace requires coal injection, the lance can quickly and accurately spray pulverized coal to meet production demands. After coal injection stops, the lance is withdrawn, and the ball valve automatically resets, effectively preventing the leakage of high-temperature gas from the furnace, thus ensuring production safety. Although this type of lance demonstrates high reliability and stability, abnormal damage may still occur under special circumstances. This typically requires professional analysis and inspection to determine the specific cause of damage and carry out corresponding maintenance.

       When the lance is damaged, although it may raise suspicions about its quality, in-depth analysis of the damage condition is crucial for resolving the issue. The lance begins its work in the blowpipe, and if abnormal damage occurs within a short period, it mainly manifests in two forms. The first is burn-through melting, which primarily occurs within the first 500mm of the lance front end in the blowpipe. The surface may show localized melting, pits of varying sizes, and melt holes, with defects forming from the outside inward. This situation often occurs shortly after the blast furnace resumes operation following a shutdown. Possible causes include system malfunctions, improper operation, poor furnace conditions, tuyere coking, system blockages, intermittent injection, hot air backflow, and air leakage at the contact point between the lance and the tuyere. The second is perforation and erosion leakage, which can occur at any part of the coal injection lance. The specific causes are related to the lance's service life, material quality, and operational methods, among other factors.

      During use, the lance may also face other issues. For example, defect areas sometimes show a trend of forming from the inside out, accompanied by erosion patterns, which may be due to quality issues with the lance tube, such as cracks or folds. In particular, welding problems in the lance tube, such as misalignment, internal weld nodules, or defects in the weld itself, can lead to such issues. Additionally, "blossoming" at the lance head is a common problem, characterized by significant scattered coal powder spraying at the nozzle, which is mostly caused by inserting the lance too deeply. The insertion position must be determined based on the tuyere, blowpipe structure, lance structure, and furnace conditions. Inserting too deeply can easily cause head burn-through and "blossoming," while inserting too shallowly may lead to erosion and damage to the tuyere sleeve.

       To extend the service life of the lance and improve its effectiveness, it is essential to prevent and address the above issues. Particularly in material selection, wear resistance and high-temperature oxidation resistance are critical. The better the material's wear resistance, the more delayed the occurrence of defects under the same operating conditions. At the same time, periodic maintenance and inspection are indispensable. Regular inspections of the lance can not only identify potential issues in a timely manner but also avoid the impact of sudden failures on production. Therefore, the correct use and maintenance of the PQ-2000 blast furnace pulverized coal injection lance are of great significance for ensuring the smooth progress of blast furnace production and the effective utilization of pulverized coal.